Valve



VALVE Filed Aug. 17, 1928 Patented Feb. 27, 1934 VALVE Arthur Baur, Ennetbaden, Switzerland, assignor to Aktiengesellschaft Brown Boveri & Oie.,

Baden, Switzerland, a joint-stock company of Switzerland Application August 17, 1928, Serial No. 300,305 In Germany August 19, 1927 3 Claims.

This invention relates to double seat valves and particularly to means for sealing a valve seat member within a valve casing.

Heretofore, double seat valves for purposes such as interchangeability of parts in assembly and economy in manufacture, have been constructed of a valve casing, a seat member sealed into the casing and a valve body cooperating with the seat. The interior of the casing has generally been finished to provide either cylindrical or conical surfaces adapted to fit similarly formed surfaces on the seat member with a high degree of accuracy. Such construction, due to the high degree of skill required on the work, is very expensive.

In an effort to avoid frequent replacements, the valve seat member has been made of material different from that used in the casing and more resistant to destructive forces operating within the Valve. When the casing and the valve seat member are made of dissimilar materials, the difference in expansion of the two materials results in leakage around the seat member.

It is, therefore, among the objects of the invention to provide a double seat valve construction of the character described, in which extreme accuracy of the contact between the casing and the seat member is not essential to proper operation of. the valve.

Another object of the invention is to provide a valve construction in which the valve seat member may be made of material having a different coefficient of expansion from that of the material from which the casing is formed, without disposed within a casing member 10. The seat member is provided with upper and lower seats, as shown, for the double valve 23. The lower valve seat portion of the seat member is freely movable relatively to the adjacent portion of the casing member upon occurrence of conditions of unequal expansion or contraction of these members. For the purpose of permitting of such relative movement, While at the same time providing a fluid-tight seal between the adjacent lower portions of the members 10 and 15, the seat member is provided with a groove 18 for receiving resilient sealing means in the form of a resilient ring 25 of substantially U-shape cross section. This ring is tensioned between the members 10 and 15, with its edges 26 pressing firmly against the same. The ring 25 is positioned as shown, so that the fluid-pressure on the high pressure side of the casing member is effective to supplement the tension in the ring at the bend 27, and press the edges 26 into firm sealing relation with the adjacent faces of the members 10 and 15.

From the foregoing, it will be seen that in my improved construction it is only necessary to provide a good fit between the face of the seat member 15, opposite the upper valve seat, and the adjacent complementary face of the casing member 10. This feature contributes toward economy and simplicity of manufacture, as distinguished from the high degree of skill required heretofore in providing accurate, fluid-tight fits at both the upper and lower faces between the casing and valve-seat members. Furthermore, in my present improved construction, unequal expansion or contraction between the members 10 and 15 is freely permissible without causing leakage between the same at either the upper or the lower valve seat, whereas this condition, in the various prior constructions, has caused an appreciable amount of leakage.

Although I have illustrated only one embodiment of the invention, it will be apparent to those skilled in the art that it is not so limited but that various modifications and changes may be made therein, without departing from the spirit thereof or from the scope of the appended claims.

What I claim is l. A double seat valve comprising a casing, a double valve seat member within said casing, said valve seat member being formed and arranged to form a groove with said casing, a single valve member contacting with said valve seat member, and a compressible substantially U- shaped ring arranged in the groove for sealing said valve seat member in fluid-tight relation against said casing.

2. A double seat valve comprising a casing, a double valve seat member within said casing, said valve seat member being formed and arranged to form a groove with said casing, a single valve member contacting with said valve seat member, and a compressible substantially U- members being grooved, and a sealing ring of substantially U-shape cross section tensioned between said members and providing a fluid-tight seal therebetween, said ring being arranged in such wise that the fluid-pressure is effective to press said ring into firm sealing relation with said members."

ARTHUR BAUR. 

